When I have stayed at a number of vacation homes I have used hot tubs - no test kit, no knowledge of water chemistry etc. So we happilly soaked for hours off an on and no one came to add anything to the water and no one told us we should.
As a guest what is OK and what isn't OK to do to both protect my family and respect that this is someone elses?
My thinking is that I would take my basic kit, test pH and OTO TC(or DPD FC/CC kit or FAS-DPD). Then test before a soak and after and bring some plain chlorox bleach with me. If the FC drops too low - I could hit it with some bleach when I get out.
Is that a sound plan?