HG Haarontstopper safe to use in an old house?

Hey guys is this safe to use for the shower drain in an old building? My shower takes forever to drain, I already removed all the reachable hair and I tried baking soda/vinegar/boiling water but it didn't help. It says it's safe for all pipes besides aliminium and zinc. I don't really want to call the rental agency as they charge a 55€ fee if the clog is caused by the tenant but I'm also scared this might cause damage to the pipes? Any positive or negative experiences with this product in an old house?