I just bought a house in Indianapolis and need it cleaned out- lots of dirty furniture and household items.

Get all of the furniture trash and tenant leftovers out of the houseDemoStrip Floor System OutRip out Ceiling in Areas with Water DamageAssess the situation and get your structural engineer to give you his opinion/report. 

If the area is a upscale neighborhood then you furniture will be a negative.

It might be surprising, but a lot of investors drive beater vehicles and live in modest houses with 20 year old furniture. 

I do recommend very strongly before you go buying the same list everyone else is buying and worry too much about dialers and the such that you take the very first right of passage that I believe every investor should take.DRIVING FOR DOLLARS.This is also probably one of the lowest cost of entry while also being one of the surest paths to success.Simply start going through the B and C areas of your town and start looking for signs of distress and abandonment.Look for the tall grass, homes that you can see right through at the windows, homes with no curtains and no furniture inside, damaged mailboxes, mailboxes with no doors, missing mailboxes, cars with expired tags which have obviously not been moved in quite awhile, etc…Once you have found 20-50 addresses, look them up on the county’s property appraiser.Here is a link to a site that will pull up the property appraiser, clerk of courts and tax collector for every county in the country. 

I have seen a lot of STRs lately for sale. or seeing a lot of furniture sales from STRS. or the STRs are moving more to medium term rentals.

This doesn't include a one-time fee of $1500-$2000 of used furniture.

There was a barbecue pit in the back yard with the remains of a trash fire in it, milk crates for lawn furniture, piles of beer bottles, and the remains of a camper that someone was living in.

Do you stage it just for photos so the furniture isn't stuck there until it sells?

Its almost impossible to fully evaluate damage if furniture and possessions are still in the unit.