Since your previous tenant has abandoned the property and this new person is a complete stranger, with no lease, it sounds like an unlawful detainer case which I've found is quicker than an eviction.

Super easy and much safer than showing up for some stranger to walk the house with you.   

Asking a stranger to let you inside their house may work for the burly guy, but for me it could be very different. 

Sure you can listen to podcasts and make productive use of that time, but I would advise against it with as much conviction an internet stranger could convey.

One person might be extremely successful at cold-calling, where another wouldn't be willing to call strangers with a gun to their head. 

How does one protect their investment when working with a stranger?

I have never been comfortable talking to strangers and in general I'm not a good salesman, YET.

If you’re selling your own home you probably are scheduling showing appointments yourself and want to be there rather than letting strangers poke around your property unsupervised.

Don't hand your money over to strangers with some kind of security/recourse. 

If you were to rent a room with other strangers, would you choose Murray?