I don’t understand what is accomplished by dulling the cutting blade. If the issue with the shaver is tarr, than all you have is a dull tarr, Maye nafke mina? For that matter, what is the specific issur of tarr? Is it the blade against the skin? Is it the closeness of the shave? If the latter, why was samm (depilitory powder) ok? How about a razor cut haircut? The razor is just used to trim the hair, not shave the head. The blade never touches the scalp. In fact, the action of the razor against the comb is not unlike the action of an electric shaver. How about a trimmer (Note 2) with a guard. A #2 would give you that stubble look I mentioned above.
It seems to me that all psak, especially psak that dealing with technology, needs a detailed explanation . Just saying “assur” is insufficient.
Note 1: If the specific issur is removal of the beard, then all of the questions above about shaving are moot.
Note 2: A trimmer works exactly like a scissors, blade against blade.
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