Rep Power: 0

I am doing a head gasket change 98 Civic DX and looking for a good way to clean off the gaskets. Head gasket, pistons, exhaust manifold, and intake manifold without doing any damage to the head or block. I am sending the head out to get machined. I've seen razor blades (being VERY careful), scotch brite pads, steel wool, brass bristles, sandpaper (which I won't try), plastic scrapers, which would you recommend? And what type of cleaner should I use? Seen brake cleaner, carb cleaner, rubbing alcohol. Any input would be great, thanks.

 
Rep Power: 211

Avoid scotchbrite, sandpaper, steel wool or sanding disks as you don't want any grit or dust getting into the engine and ruining the internals.

Most people use brake cleaner spray + razor blade held in a vertical or near vertical position to avoid scratching the mating surfaces.

 
Rep Power: 518

The head gasket is steel, it comes off clean and leaves only colored residue that usually will wipe off with a shop towel and carb spray.
If it doesn't wipe off, a single edge razor blade is the most you'd need to scrape the remains away. I don't worry about leftover spots of color as long as it's SMOOTH.
Remember, it doesn't need to be bare exposed metal, it just needs to be perfectly flat and smooth.

Before you send it to the machine shop, NOTE HOW SMOOTH THE FINISH IS! It's almost glass smooth where the head gasket has to seal. You can see machining marks but you almost can't feel them.
The machinist needs to make his work just as smooth as the factory made it. (maybe 15-30 RA)
If the surface finish is left too rough, it can leak past the head gasket.

NEVER EVER use scotchbrite of any kind. If that grit gets in the oil the bearings can be trashed in short order.
Nor wire brush, steel wool, or sandpaper. You'd be begging for trashed bearings.