At first I was extremely suspicious of these particular sponges because they claim to not scratch the surface and it's "all natural". So, I gave it a try and I have to say, I'm very impressed. I bought a 6 pack a month ago and I'm still using the first one. I cook almost every night and I do my fair share of cleaning dishes. It does get off the gunk and grease on the bottom of those pans. They don't scratch any surfaces and it's just as heavy duty as scotch brite heavy duty. I'm hooked.