RL: thanks and i'll give it a try cause my bride has been complaining for years about me making a few dents in our oak hardwood floors with me bringing in stuff out of my garage so i could try to get organized...
Good luck. Just remember that the heat will soften the finish, so be gentle on it when it's hot. If you have an inconspicuous area you can practice, you know the drill.
The last time I used this technique was on a hammer dented pine bed with a water based urethane over an alkyd semi-transparent "stain". In that case, the urethane blistered, wrinkled and peeled. It initially looked awful (like boiled chicken skin), but I was able to refinish it with a spot touchup in a way that now only I can find the damage. Don't be too discouraged if the dent pops out but the finish is damaged. Urethane may be hard to spot treat perfectly, but if you're careful, the results can be less visible than the dent was initially. If you do damage the finish, just be very careful removing any damage. Remember that any oil based stain will not be affected by the heat (since it resides under the surface of the grain), and if you don't disturb the stain, you should be able to retouch the clear finish on top without a visible disaster. With my alkyd stain, I did have to touch up the stain first, before I brushed on more satin urethane.
Before that, I used it on a linseed oil finished walnut rifle stock that was dented on metal on a bench. That came back flawlessly after it was rubbed down with some more oil.