My T doesn't swear that much, but I do frequently!!!!!
I drop F bombs left and right. I also curse a lot at home. I know--lovely for a mother--and my husband is none too fond of it but it works for me! If someone is offended by it though I try to honor the need and curb my enthusiasm.
If your T is using language you are uncomfortable with tell him or her. If you want to curse at home and are not offending anyone, go for it! Yes, I think it can be very therapeutic to rant...
Peace