Why can't we find razor blades?

Now that the painters have moved on we are faced with cleaning up the floors. Our painters mostly cleaned up after themselves, but alas they did not want to scape up the droppings of previous painters. Our floors are badly speckled- especially in the master bedroom and in the guest room.

Yesterday morning I spent my child-free time with a bucket of Mr Clean and a razor, moving along tile by tile scraping off the old paint (and lord knows what else- there was a lot of mystery sticky) and scrubbing each tile with cleaner. I finished about half the TV room. By then I had gone through maybe 6 razor blades.

Andy was at Home Depot and tried to get new blades there. (You know, those packs of 6 or ten blades, each wrapped up in a little paper sleeve??) No luck. We tried about 10 hardware stores throughout the day. No one had razors, although we were recommended to try muratic acid to get the stuff off the floors. Finally we broke down and bought a bottle... It frightens me, but we'll see how it works.

But how will we clean the paint off the windows?

Where can we find razor blades in Guadalajara?