All wool soakers should be hand washed in lukewarm to warm water, never too hot.
Extreme temperatures may ruin the shape and feel. Wool is a natural fiber that has inherent antibacterial properties, so wet soakers need only be left to dry. When solids get on the soaker, make sure to give it a hand-wash with special wool detergent, I use Imse Vimse’s wool care product, but any special wool soap will do.
If the soaker feels like its not holding its weight in wetness, and seems to be leaking right away, it may need to be lanolized.
To do this:
take a large pea-sized amount of lanolin and dissolve it in about a cup or so of boiling hot water. Then add this to lukewarm water (about half a sink-full) and a splash of wool soap. Add your soaker to this mixture, making sure to remove all solids before submersion. Do not wring the soaker, instead swish and scrub gently. Let stand for at least a half hour. Do not rinse, pat dry with a towel.