I believe for an investment property in CH the bank may lend max 75% subject to rent covering mortgage at a 5% rate that is used for stress test
I often read about this kind of creative “recycling equity” / no money down financing from investors in RE in US or UK. I don’t think it works for a small investor in CH. Consider the different tax rules, stronger tenant protection laws, SNB regulations, competition from professionally run pension funds and low rental yields.
Swiss real estate discussed here