And, while we're having this talk, why are you asking ME to come up with your meagre 5% deposit for your primary?

I'd keep it simple, Application denied.Your going to have to make this type of decision on each applicant.Do you have a set criteria for your rentals.. credit score number, income = like 3 times the rent, verifiable rental history,, should show deposit returned , no lease infractions... if deposit wasn't returned what was reason, was lease term completed..  

Yes, it's kind of a shot in the dark but if they pay your deposit and don't pop on any of your other checks then run with it.

Earnest money deposits vary by location.

The reason it's non-traditional to invest in buy n holds vs 401k is because there are no 'got real estate' commercials but plenty of banks, brokerages and financial advisors marketing endlessly.

I'm pretty old-school in my methods (still get actual checks, not direct deposits) and I'm starting to see the need to move into this decade.

How do most property management companies handle security deposits?

Use a phone app and deposit the check.

Always have a paper trail for where your funds come from esp for that 2 month period leading up to your applying for a mortgage.I have a tenant who likes to pay their rent in cash only.This created a problem for me as the deposits were just that cash with no record other than the rent receipt I was unable to claim 800 per month in income for a recent purchase because of this.Now I will only accept a traceable form of payment for rent. 

If they insist on no financing contingency, negotiate down the earnest money deposit to be a sum of money you are willing/able to give up.