I, too, have seen the commercials and do not plan to use the big abrasive blocks they offer. The reasons why are cost and quality of the job. With abrasive strippers, the high spots are bound to be removed. This might be fine when you are sanding something flat but the abrasive will quickly erode corners and molding detail. Sanding carvings would be impossible.
It would appear that the sanding blocks would leave rather large surface scratches. To remove these you would have to work back down from probably 80 grit paper to 150 or 220 grit, which would be a lot more work than a chemical stripper to get a good surface for finishing. And $20 for what amounts to about 8-10 sheets of 50 grit sand paper doesn't seem attractive to me.
I have tried many of the chemical strippers and will tell you what I have found over a lot of jobs over a lot of years. Take it for what it is worth. All chemical strippers are not the same. For most jobs, I prefer Citristrip. It is safer and more pleasant to use than any other product that I have found. They have a web site (www.citristrip.com) that is very helpful when you have questions about unusual conditions or substrates. If you try it or any other chemical stripper, be sure to follow manufacturers directions, particularly as regards safety issues. I also find that their paint remover wash does a good job of removing any final traces of the old finish. For removing multiple coats of old paint, Peel Away is a great product since you can put it on, leave it for a day or 2 and the old finish will be ready for you to remove. Nothing like letting the product do the work and it is not real objectionable while it is working. Be sure to keep kids and pets away from it while it is working though.
There are commercial places that will strip for you. Personally, I have not tried them and would be affraid to on anything that is glued together. Everything that I have heard is that the dip tank type strippers are pretty tough on glue joints.