I usually mix a 1 to 4 ratio (vinegar 1, water 4) but stronger if the stain is bad. 

The itch to pull the trigger on my first deal is getting stronger and stronger!

When the lure of travel is stronger than my control issues and profit concerns, we'll flip it over to a property manager.  

Their case for legal possession is much stronger than that of someone who just broke in.Some of the scenarios previously suggested may have success if you are a little aggressive.- Wait till they leave for the day to check on your vacant property and when you find that your locks are broken (i.e. your keys don't work), you hire a locksmith to change them or do it yourself.- Gain entry to YOUR house, through whatever means, and immediately temporarily rent it with a written lease to your very large, muscular, aggressive, friend...  :-) .In Texas I have registered electronically with the Justice Courts in the counties where I have property and filing an eviction is relatively painless, even more so for squatters.

I also like having a stronger exit strategy should I want/need to get out. 

Because of this experience, my lease is a lot stronger, I am wiser and my investment is better cared for. 

If they are interested in cash flows, the new payor is a stronger payor than the old payor, and the interest they are receiving is right, they may choose to ignore the breaking of the loan covenants.

Guidant Financial charges $3000 to set it up (the most expensive I've found so-far) but they 'sell it' based on claims of superior support as well as a "safer, stronger system" than the others.

If you contact a hard money lender, they can typically provide you a qualification letter for your offer to help you submit a stronger offer.  

Its OK for a quick fix but you need to treat it with something stronger to avoid it coming back & it will !!