nospambob wrote:
Our sink is slowly having more trouble emptying as we run the cold
water out of the hot line in the morning. A plumber took the trap off
and manually chiseled out the gunk in the horizontal section going
into the wall. My knees wont support that type of work so I'm
wondering if there are any other ideas to try. Would ammonia be a
start?

"chiseled" out the gunk"

What did the plumber suggest? Why didn't he attempt to snake it when he
had it apart? Or snake through the vent? Me thinks you're looking for
the low or no cost miracle fix, you're not going to find.