Nah, the holes under the rim are for rinsing the sides. The amount of
water
they furnish the bowl is miniscule.

Sorry your wrong! Not long ago I fixed a friends toilet by giving it
some acid down the dip tube and in the bowl.

The crud that flowed out was amazing.

The rim holes add enough water to get the good flush going....

when you flush and see just a swirl sediment has likely plugged in
interior water passages.....

Easily fixed with acid in well under a half hour