cleaning dirty hardwood floors??

[Adam Drummond]

I have an older home with original hardwood floors which are prob 70-80 years old.  Floors were refinished 5-7 years ago, but the prev tenants made them pretty disgusting.  Any suggestions on the best way to scrub / clean them up, and make them shine again without actually refinishing them.  I wasn't sure if detergent and a mop would harm the wood floors or not.  Any suggestions would be great.  Thanks in advance.

Adam