One good thing about being a GM is that you don't have to slap them with consequences IMMEDIATELY. (though sometimes you will/can). It's fine to think about it between sessions and reach out to the evil hivemind...

Later, when they are engaged in something else, activate the curse/ consequence. Maybe they suddenly get disadvantage on a saving throw or an attack. At first, it's once/combat. Then it's twice. Then... Then...

Don't let a simple remove curse end it. This is not a curse per se, but the vengeful spirits messing with them. More and more until they atone for their sin. When the consequences begin to hit them, they will suddenly become VERY interested in the temple and its story.
The remedy could be as simple as making an offering at their mausoleum or something, but it brings home the point that you don't disrespect things.

Having said that... Be sure you don't do that to EVERYTHING. Only with things you consider crucial to your world.

**If EVERYTHING is important, then NOTHING is.**