I switched to Google's keyboard (gboard) a while back, and I have to say: it's WAY better.
Also, regardless of which one you all use, *MAKE SURE to go into your settings and TURN OFF the option to "IMPROVE" the keyboard!* Neither company has any right to be READING YOUR MESSAGES.
To answer your question though: in settings is the option to block explicit words. It's blocked by default, but you can unblock them. You may still need to add those words to your dictionary though. Here's how to do that efficiently: (after you've turned off the explicit words block) every time you type in a curse word *BEFORE YOU HIT SPACE* tap the word in the bar at then the very top of the keyboard (where it has word suggestions). Doing this adds the word to the dictionary (and doing it before hitting space keeps the keyboard from "auto-correcting" the word before you have a chance to save it.
