Since it's a homemade bong, you should definitely go for it! Although, don't use it in glass/acrylic bongs-- they're very hard to clean, afterwards! I've heard orange soda works, just like Brawla, but I've never tried.
Yea it will bro, make it ice cold, and it will taste a bit like coke, i like Red Kool-aid!!!! O and its GOOOD
Ya ive never personaly tried it but i think the weed resin would deminish the taste of the soda (which most people that have tried it say all you can taste is carbonation) per bong rip
I wouldn't do it unless the soda is totally flat. Breathing in co2 isn't for me. Orange juice would be ok if your after the orange taste. I use straight water and enjoy the taste personally. Cleaning nasty soda out of your pipe can't be fun either.