Having a bit of trouble getting a chain slider sorted.

I tried a cheap Chinese one off ebay and the rubber was too soft and it chewed it up and covered the chain with bits of rubber.

I have just tried another one which is supposed to be made in Japan and a good quality. The rubber was a little harder, but it is still chewing out very quickly and leaving rubber everywhere.

What are other people running? And has anyone had a similar experience and it stopped chewing out once it was worn in a bit more?