Originally Posted by
DireStraights
Not really. Japanese sword polishers buy stones with toxic inclusions frequently to save money. They go through expensive stones so fast that for a new togishi it is probably the only real option.
The common practice is to use a nail or hard piece of steel to dig out the toxic areas below the honing plane. You can get an uchigumori that would normally be 600$+ for 100-200$ if you take the time to remove the toxic areas.
I have a new phone/camera so I will post my collection soon. It is getting quite large even with the Jnats I had to sell. I figure by the time I'm 30 the pile will be insane.(24 now, been seriously collecting natural hones for a year or so)