Diffs... Help/advice on grease?

[Gazzalene]

I have done a search on this AND a few other mods but the posts in many cases are very old with the pictures removed and members not posting for many years.
Looking at posts it seems the axles/diffs are a weak point. Some say that thicker oil is preferred. The kit comes with 20k diff oil ,I bought 30k thining that was a good bit thicker BUT since read guys are using 500k!!!!!
I have gone the other way and bought some red n tacky grease.
I can not find out for sure how much to use. Do I totally fill the diff case,try to fill every void? Do not want to cram it in and find it blows the gears.Also read a post where he uses grease around the cv drive holes then fills with oil to stop leakage.
I have seen guys on YT wedge silicon ear plugs into some diffs. Need advice here please. Do I go thick or run stock as manual suggests.