I'm not sure if it is recommended with how skittish they can be about water. There are drops you can buy for flea protection that you can apply between their shoulders. Depending on the brand it can be very effective but read the ingredients. Some of the drops can be irritating to their skin, you just have to do your homework.
Sorry I'm really not sure! But I have used the dawn dishwashing liquid as Bryan Sparlin suggested and it does work. And totally safe.
Look up using dawn blue dishwashing liquid instructions. It's safe.
Thank you
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