These spatula cleaners are great. They penetrate every crack. BUT . This putty and others I've ordered come in the form of useless slime. They're all made in China and apparently won't survive "on the water" on a trip to America. This product came out of the box with the consistency of snot (the mental image is as disgusting as the reality) and was completely unusable. If this type of putty is ok then it's a great way to fix cracks but the last few pairs I've ordered have been completely useless.