Home button & power button not working unless submerged in water

I have had a this Samsung S7 for over a year now; almost everyday; I wash it with soap & water because I'm a clean freak & it makes it feel new. The washing process is similar to hands; put soap everywhere; & either rinse or dunk (if you're on the go). This phone has been taking that for this long until tonight July 14 2018 (going into); I washed it & used the phone with earphones for about 3 hours; suddenly the phone is bringing up google assistant every few seconds as if I'm holding the home button. It works for a bit longer then after about 20 mins; nothing; I can't get the home button to work, nor the power button... however; the volume buttons are working just fine along with the rest of the phone.. I figured that there must be something stuck under the buttons somehow; I fill a little tupperware thingy with water & dunk the phone & pull it out; nothing still. (I dunked instead of rinse to get into deeper places) I decide to see if the buttons work under the water; at first no. But after about a minute of clicking both randomly; suddenly the power button works; then the home button. I pull the phone out; for about a minute; the phone works normally again. Then both stop working again; I've done this repeatedly & haven't got a solution that works out of water. Please help! This is a really weird problem; normally you don't need to dunk electronics to get them to work lol & I'm not a fish so....