I've learned the hard way that a lot of the liens on the property carries over to the new owner minus the water.

After a couple of years we carried out an energy efficiency retrofit and added a second bath along with 2-more bedrooms.  

If you're looking to qualify for more properties make sure when you're filing your tax returns you're not taking losses on each property otherwise you're income will have to carry those losses.

Jet rodder is one method , its like a power washer , it will scrub the inside of the pipe .

You can get more detailed, telling about rehab costs, carrying costs, sales costs, etc and I would.Otherwise, @Mark F. has great suggestions building the rapport and getting to the pain points and their bottom line.  

Keep that in mind.My most recent seller-carries were at 6%, long-term.  

That means you will have to be able to carry two and sometimes 3 deals at once.

Plus I would not be able to carry the mortgage by myself until the several months of renovations are completed.  

You'll also need money to carry yourself through non-peak seasons when rent is not being collected and you've got utilities that are still running. 

I currently have my accounts with a big bank, mostly because they carry my personal mortgage.