Prig is not a naughty word. Pussy might be. Shit definitely is.
If the Good Lord had designed us to never take a crap I would agree. He saw things differently. I dare say even the prigs in here take a crap on average once a day, and some more often than that here in threads.
Do not take His name in vain. Use naughty words all you want, but never towards your mother or father. Them’s the rules on cursing. Everything else is prigish. Cursing is impolite, but not a sin.