When your soaker gets dirty, or starts to have a smell, it's time to wash it.
Rinse your wool well in cool water and gently squeeze out excess water. This is necessary to remove the salts in the wool that dry the fibers and eventually retain odor. You may decide to repeat the rinse. Fill your sink, a large pot, or a washtub with lukewarm water and add a wool wash or gentle soap. If it's something you feel comfortable washing your baby with, then it's probably a good choice for your soakers. Do NOT use Woolite or other similar products; it will damage your wool.
Gently wash your covers. It is important to treat your wet wool carefully so you don't cause it to shrink and felt. A wool wash bar is a great way to clean stains that get on the wool. Soak covers for a while, drain and rinse to remove soap and dirt residue.
Some people like to use a lanolin enriched wool wash, which will replace some of the lanolin each time you wash. I like to do them separately because I find it harder to get the wool completely clean with the lanolin in there, but do what works for you!
How I lanolize
Read below or download and print these instructions.
Fill the sink or other washtub or pot that you plan to lanolize in with tepid water.
If your item isn't already wet from washing, put it in now and let it soak for a minute to get fully wet.
Fill up a clean jar or bottle with very hot water. I have repurposed an old peanut butter jar for this. You can either put the jar (without the lid) in the microwave, or you can heat some water in a teakettle and then pour it in the jar. To the hot water I add a squirt of lanolin. It will float on the top of the water in a big fat glob, but will start to melt because it's hot.
To that I add a few drops of liquid soap. I like castille soap, but any soap that will break up fats would work.
The soap will start to break up the lanolin glob immediately, and will start to turn the water cloudy white. Then I put the lid on and shake it up really well.
Add the milky lanolin-soap-water mixture to your pot or sink.
Turn your soaker inside out and put it in the water.
Let it soak for a few minutes and then move it gently around. Leave it in for at least 15 minutes, but I often just walk away and come back and deal with it later or in the morning.
When you're ready to take the soaker out, gently squeeze out the water, turn it right side out, and then lay it on a towel.
Roll it up to get as much water out of it as you can. You can also do this in your washing machine spin cycle, if you are confident you know your machine well. Do not use a spin cycle that will end and then fill with water.
Lay flat, and arrange into shape. You may need to stretch it a bit lengthwise to get it back into shape; otherwise it will tend to get shorter and fatter. Allow to dry. If you have added too much lanolin, your wool may feel a little sticky- this is OK. If they are very sticky you can always wash again with a bit of soap, but I actually like them to be a bit tacky.
Colored soakers may bleed into your wash water. I recommend washing dark soakers separate from light colored ones, at least until you know they won’t bleed.
Do not dry soakers by setting them in the sun. The natural bleaching action of the sun may also fade the color, especially in hand-dyed items, and the sunlight can break down the wool fibers faster.
Do not wash your soaker in the washing machine or dry it in the dryer. This will cause your soaker to shrink.
Help, I felted my soaker!
The combination of heat and friction will cause wool to shrink and bind together. If you (or someone who shall remain nameless) accidentally machine washed and/or dried your wool, there is something you can try.
Fill a sink or pot with lukewarm water and a LOT of hair conditioner. I use the cheap stuff for this. Soak the wool for a bit in this mixture. Then gently stretch, soak, and stretch some more. Depending on how much it shrank, you might even get it back to it's original size this way.
You'll want to wash with soap again to get all of the conditioner out (gently!) and rinse a bit. Once you get it all rinsed out, be sure to lanolize again, as this process will have stripped it out.