How do you prevent co-mingling of funds?

[Bob Asad]

If I have 2 rental properties and charging 1st, last, and security; can I take the last and security for both places (combined) and put them into a Bank of America savings account?

In other words, I already have a checking and savings with BoA, but I would create a 2nd savings account (within my regular account) and put all the rental properties last months and security into that account (combined).

Is this the correct way to prevent co-mingling of funds, or what would you recommend?