I recently tried it for a 40 gallon for some leopard geckos.I used something called roctite mixed with it to make it much harder and it worked well(I also use a water based polyurathane to water proof it.
Alone I dont like the Excavator, its just too crumbly and doesnt dry hard enough to be of use. Its not easy to clean either.
I took my leos out and put a young bullsnake in the cage instead, he likes it just fine. But eventually even spot cleaning wont be enough and it will start to stink so I am hoping to get 6 mnths out of it.
Also I taped saran wrap on the tank before I used the excavator/roctite mix so i can remove it easier when it starts looking bad.
I wont use it again though.