It is similar, but different, as there are actually about 8 different type of "tax sales".
The houses that I am speaking about have already been through at least one tax sale and no one bid on them, therefore the county (who officially enters the first "starting" bid) bought the homes officially. They have been held on the county books and probably offered at several tax sales, but no investor was interested and the county still ownes them.
This is why they all usually need fixing up. Some quite a lot of work is needed.
As far as reclaimation periods, these have already passed and there is no chance of anyone reclaiming these properties. They are often referred to as "surplus lands"
Due diligence is an absolute must as there is never a guarantee of any kind to the condition of the property.
The only kinds of liens that may still exist on these is usually a lien from another governmental agency such as CITY, COUNTY, STATE, FEDERAL.
I am buying a duplex valued at 45K in its current condition for only 1K. So financing is not an option here, you must have the whole amount ($1,000.00) in order to start the bid process. If someone outbids you and you cant outbid him, then he becomes the winner of the property and from what he gives them they return your money, so no chance to loose your money, but it is tied up for the duration of the bid process.