i've never really had any problems with the basic hozan spanner. i typically throw a pipe over one end (when i'm loosening a ring), make sure that everything is lined up, and push down. the only real issue is with it falling off of the ring, but i find that if you angle the wheel slightly so that the wrench rests against the cog when you're torquing, that won't occur.

i've never deformed any lock ring notches with the single tooth design, except on the known-to-be-fragile dura ace bottom brackets. you really do need the bbt-7 tool to spread the forces over several notches.