Any ideas on eliminating build up in a grinder pump basin besides enzymes andhow effective are enzymes and how often do you need to introduce them

This is not a septic tank wherer solids are converted to liquid, If you have gunk built up in the pit it will have to be cleaned out by hand.
Here's a link that will explain about ejector systems and how to maintain them: Maintenance Guide for Septic Pumps, Sewage Ejector Pumps, Septic Grinder Pumps, Septic Effluent Pumps and Sump Pumps
Good luck, Tom