Is there a better way than freeze-thaw to open hunks of fragile sandstone to expose the wonders within?

[SteveE]

In Pennsylvania USA, in the Old Port Formation, some trilobites are exposed in the scree and talus below coarse sandstone horizons.  They tend to be very fragile (image below).  My question is..... what's the best way to open large hunks of this rock, hoping for intact fossils within?  I'm thinking about trying freeze thaw, but opted to check in here for alternatives or helpful tips.   Anyone?  Thanks!