You have to do 'purify mind first'. Let it finish, i.e. wait until the vllager no longer says 'Purifying..'. Any villager coming into the area will abort the meditation so have your finger on the space bar, ready to PAUSE and remove anyone incoming. Having the kiddies in the nursery school helps somewhat.
Then go put the soap in the pond and get clean. Again, be sure you let him finish. And, keep your fire going.

try washing them in the pool with soap

Had 3 teachers in school, put oldest male in corner with flutes, made sure there was soap, made sure the kids were in school, kept moving the teachers, once oldest male had yellow sparkles, picked him up to get the soap, no one else in pool, put him the pool, kept the kids busy in school, once he had yellow and white sparkels and he gets out of the pool, moved him to the tree, then the game took over. good luck, especially with the kids.