My suggestion is to not use the papertowel method. I don't want a half inch of root sticking out before I plant either. Best method for 100% germination is to soak seeds in tepid water for @24hours, most will crack by then, and place directly into grow medium. I grow soil and place directly into soil with great success, but, if cold or low humidity, I start in rockwool and control the temp/hum in a dome until seedling shows and then to soil with the rockwool plug. Wouldn't throw out a floater either, though I don't allow them to float beyond half a day, by shaking container until they sink. I've planted and grown seeds that floated and never sank.