The key is keeping the toys well lubed!
Came across this someplace regarding strap-on anal sex but assume it is equally applicable for other orifices:
Eight Rules Regarding Lubrication for Anal Sex Using a Strap-On:
Rule #1: There is no such thing as too much lube.
Rule #2: Use a lot of lube.
Rule #3: Make sure you get the lube deep INSIDE, not just around the opening. (Use a lube injector, they are much cheaper than a trip to the doctor or hospital to repair tears.)
Rule #4: When you think you have applied enough lube ... add more. A lot more.
Rule #5: Replenish the lube BEFORE you think you need more.
Rule #6: Replenish the lube BEFORE you think you need more.
Rule #7: If you think you used too much lube than necessary when you are done, you are wrong: it was just right.
Rule #8: There is no such thing as too much lube.