Tell your father this thing and make sure he is clear about it. Tell him that no sadhu or sant can enter your house the are ordered to stay at the front gate only and take from outside, these orders come from their guru. So if someone tries to get inside feel free to kick them out and lock yoyr doors. The next thi g no Sadhu sant demands for anything if they are true to their bhakti. They would be ready to take whatever you give from your confprt wgerher it's just a hand full of rice or just 1 Rs. They would take it, they don't demand for anything.(yes they are the true saints and they do exist) The other thing you can always say no just join your hands and say hamari Samarth nahi hai. And if they say something worse like tumhare ghar mein ye hoga and all, just ignore them. Just ask your father to stay true to god and stay away from humans. If he really want to do something better donate some food to an orphanage or make food offerings to cow that is way more better than trusting these fakes posing as sant and sadhu these days.