Hi Teresa -
I have the Hearthkit, which has worked well for me. I have an old 
oven that works okay but can use some extra help.
It's heavy so I don't take it out often. For minor cleans, I wipe it 
down with a rag and water. I also do that before a major cleaning. 
For major cleaning, I leave it in the oven while I run the oven on a 
self-clean cycle. I remove the sides first so the air can circulate 
more freely.
If I didn't have a self cleaning oven, I would probably leave it on 
my outdoor grill for a while to burn most of the food off. It's too 
big to use on my outdoor grill (and still have room to grill) so 
there I use a leftover tile from granite work I had done.
Leigh