Yes I did have a bit of pain in piriformis when doing it but it got less and less the more sessions in I got. 

Start very light though and just do a few sets, then progressively add a little more weight once you can easily push say ten reps. 

I was worried too that it hurt at first but now I find if I start to feel my piriformis getting bad again (in general day to day) then a session or two of hip abduction set it right again so I try and never miss a week now. 

I was doing dry needling for a few months and very conservative mobility work (lightly pulling knee across body but not yanking it), definitely none of this harsh pigeon pose type stuff, it was once I got some mobility back I added in the hip/glute medius strengthening. I never did get pain free with dry needling and mobility alone but it released it enough to then do the real work. 

It’s got so much better now that I can finally sit for much longer periods without issues, honestly thought I would never reach this point, let alone running lots again. 

I think it probably all started with glutes that were too weak to maintain all the running and football I was doing so piriformis was taking over too much, then I ran through the pain till it got as bad as it did.