Do you have to be in a state of grace at the start of a process where you receive a plenary indulgence?

I was reading [this question](https://christianity.stackexchange.com/questions/104812/do-you-have-to-be-in-a-state-of-grace-to-be-invested-with-the-brown-scapular) about the Brown Scapular, which got me thinking. If you can go to confession within 7 days of some indulgences and the ordinary parts of an indulgence include receiving communion and going to confession (not in that order if you have mortal sins), can you start the process (i.e. make a pilgrimage) and then go to confession, or do you need to go to confession first?