How do melee classes kill effectivly in hell?

[Crystalion]

Assuming the character has a mid/low damage and lower chances to hit, against high hp monsters, the life regeneration must be stopped. A solution is to poison them. Those poison immune can be killed by 'open wounds' items, and physical and posion immunes only by 'prevent monster heal'.

While, as of v1.10s, afaik, open wounds is only carried by skills (i.e. attacks) that are in some sense "physical" that "succeed", and it is true that a purely "physical" attack does not "succeed" vs. a physical immune, iirc such an attack with an elemental adder that the monster is not immune to will nonetheless "succeed" thereby triggering the Open Wounds effect (which does not care about physical immunity per se).

My recollection can be easily put to the test: go bare hand normal attack some PI monsters while wearing OW stuff (armor etc.) and observe that they never are harmed--then pull a weenie cold, fire, or lightning charm out of your cube and see if you can cause them to suffer the obvious OW HP dropping.