Deleting blocks efficiently

I’ve been uploading equipment from a playground manufacturer into a rhino model for a larger park design. The file is beginning to move very slowly. I’m assuming this is because these objects have many layers + blocks. I’ve tried deleting blocks and unnecessary layers in a separate rhino file before copying them over.
Explodeblocks doesn’t explode everything when I’ve selected all, and so I’m stuck in blockmanager trying to get rid of each nested block definition. IT’s taking over an hour for each piece of play equipment and I can’t even isolate everything I want to delete. Is there a faster way to do this? Or a faster way to package these objects so that they down weigh down my file?

In Rhino 6, without selecting anything, type in ExplodeBlock then use the AllBlocks option. Then select everything. It will explode everything including nested blocks.

Then if you want to clear out all the block definitions out of the model run the Purge command. That will remove any definitions not being used.

Thanks @scottd !