Yes and Yes. We use razors, scrapers and steel wool when necessary to remove plaster, paint, texture, tape, stickers, and other debris from windows. These tools, when used properly, remove debris from quality glass without scratching the surface. That being said, we don’t use razor blades on tempered/heat treated glass. (See tempered glass). Steel wool (#0000) and brass wool we use is softer than glass and will not scratch it. Sand, dirt, and concrete particles can scratch glass when trapped on anything dragged across the glass (whether a squeegee, steel wool, or a rag). Therefore we use fresh steel wool, squeegees, and rags on each job. Be advised: while steel wool and brass wool will not scratch glass, other cleaning abrasives like SOS pads will absolutely scratch it.