I use pretty good grammar online, but in real life.. Pffffffffftttt.. I can't even hold a conversation without multiple fails and I'm shy, so yeah right. And I make up the weirdest things to use as substitutes for swear words.
Here's some,

Fuck - Funnel cakes
Shit - Shishkabobs
Bitch - Beach/Bench
Damn - Dipidydoopity
Etc.
I also say weird things when I fail at saying stuff,
Examples,
Crudderjacks
Truck
Firetruck
Biboopbaaa
CHIP!
(Don't even ask..)