I think
this Thread (from the English Forum - found by searching 'cleaning AHV'!) might have links which will give you the answers to your question.
It's never a bad idea to do a search before posting questions which are pretty sure to have been asked umpteen times before.
Sure, there are folk here who will read your New Thread and will know the answers, but the thrill of replying to identical questions or looking up the same old links for people who don't search for themselves does tend to pall after the first thirty times or so.
And had I realised
you’ve been here for thirty years…