We've kept bettas in 1 gal bowels doing 75% water changes every 2 weeks. But we feed our betta one pellet at a time to prevent any from rotting in crevices in the substrate. With the water change I vacuum the substrate very thoroughly. Bettas I believe don't need pristine conditions.
1 gal bowels? That's crappy.
Poking fun at the hilarious typo aside, bettas think male guppies are other bettas. That's incredibly unlikely to work. I keep mine in a 10 at 80F with some snails. He's killed some, but mostly ignores them.