Hello wanted to get some advice here. 

Noticed water dripping sounds when my AC is on. Baseboards also showing water damage and wear. Had my handyman come to open the wall. Found water dripping from the p trap. He took out the pipe and found a chunk of gunk. Gunk looks like a ball of snott and dead roaches. Ickkk. Pipe has been replaced and made sure that the rest of the line wasnt clogged. AC now running and no more dripping. 

It seems that this pipe connects with the bathroom vanity sink pipe. Is this the primary AC drainage or secondary line? 
How would I make sure it doesn’t clog again without opening up the wall and replacing a pipe? Like I know I can use a shop vac and connect it from outside but would that help if the pipe that was clogged connects with the sink line? Or would snaking be the recommended option?

My outdoor ac drainage port wasn’t dripping. And the pan under my AC unit was dry too. 
My vanity sink and bathtub arent backed up with water either. 

My AC guy usually puts a couple of tablets into the AC drainage pipe opening in the attic but Im not sure if this would have prevented this.

Would appreciate any suggestions, advice, or solutions. Please and thank you. 

AC Drain Line Clogged Nightmare