I have heard that bleach can be a better drain opener than regular drain openers. I have used it successfully on slow drains. Bleach is so caustic that it can denature organ matter. In theory, so can chemical drain openers, which are part bleach, part lye, and mostly soap to make the clogs slippery to help clear the drain.
The four bottles of $1 drain openers that I bought at Walmart didn't help my stopped up disposal. They seem worthless. Yesterday I poured a gallon of cheap bleach that I got at Menards into my stopped-up sink. This morning I tried running the disposal. At first, it seemed to be still blocked, but then the drain cleared.
I'm very pleased that this worked. The last time this happened I paid a plumber to clear the drain. All he used was a plunger, although he had to work pretty hard at it.
Maybe the combination of bleach and drain opener is what worked.
My old plunger which is made out of plastic broke. So I ordered a "professional" plunger which just barely arrived.