Another way would be to record the rent at full value.
Record the actual amount received & and deposited.
Issue a Credit memo for any approved rental offset, or expenses by the renter
While the way SkinnyRaven suggests will get the expenses in the correct GL account. using the deposit screen.
By issues credit memos - you can track by the rentee or property, the credit or rental offset. Each invoice has a history button that show when and what was credit against the invoice. Plus there are some reports, select credit memos as the transaction. And see what is happening in that area.
A lot depends on what information will help you in managing your properties.
An example, you might find that the paint purchases by renters. is costing you more that what you would spend if you provide the paint. There are many different types, quality, a wide price range. Then again, you might not want to deal with buying the paint. It all depends on what is important to you.