Recently I watched a Dr.Mat video in which he speaks against using alum blocks.
I thought , what's he talking about, I swear by them.

The last couple of shaves I've had I took a thin chunk out of my cheek on the second pass , South to north, directly where I place my alum coated fingers on the first pass.

The cuts are not uniform like the usual razor cuts these ones are ragged and uneven.

It's obvious to me that the blade is getting stuck on the alum and skipping...
Maybe it's time to try the small cloth technique :/