I like the grease guns from here,
https://locknlube.com/

Especially this one,

https://locknlube.com/collections/g...-b1-2-batteries-locknlube-grease-coupler

Put one of these on the end and it’ll stay put till you release it,
https://locknlube.com/collections/locknlube-grease-coupler

Clogged grease fittings, this will help clear them,
https://locknlube.com/collections/grease-buster

Ronnie