Three years ago, when I received threats from a couple of escorts, I started to use Google Voice. I usually make the first contact with this number if the provider has no references. If I like him and we click, I share my personal number. Whether to use WhatsApp or not is up to him, but I do love WhatsApp!
As I am now traveling more often, specially South of Rio Grande, I am considering a burner phone to use local chips and hide my American origin, just like I did in Argentina last trip, avoiding the extra fees for foreigners.