this might sound strange!!! i was thinking about dumping my voltage regulator in a small container filled with car engine oil
instead of attaching a heat sink... is engine oil an insulator? forgive my ignorance, im just trying to come up with better solutions.
They do that for seriously large transformers and similar units that have large surface area. You can't use any oil,
you'd have to check specs (google will tell you). But for small devices, you have no hope. Practicalities of containment and sealing,
just a lot of effort for little value. Besides, the MOST important spec is how FAST you can get the heat away from the regulator.
If you want to try it, go for it, practical is the best way to learn. The theory itself is fine.
Added: Some of the new EVs are cooling their Lithium battery packs with liquid !! ie Tesla etc Actually pumping it OVER the 44-66
lithium cells @ 180-280VDC 100-300A. We're still considering it ... lots to worry about :-)