Toilets, Sinks, Showers, Tubs and Disposals - grout mess

Hello I have a bit of a problem. About a year ago my husband and I tried to re tile our shower. My husband was not sure how to do it and ended up with redish brown grout all over the shower walls. We have been working on it off and on for the past year. We have some toxic acid stuff that I am affraid to use. The acid doesn't seem to get all the grout off. We have had to use a drummel to scrape off some of the remaining grout. I am not affraid of elbow grease but, I need something that works. Does anyone have any ideas about how to remove the excess grout from our shower. I would really appriciate any and all advise. Thank you :D

Excess grout should be wiped up as you go with damp sponge. Once it dries it is like concrete because it is cement-based. Removing it is tends to be next to be very difficult. Some report success soaking with water and forcing it off with pieces of oak wood that can be resharpened as needed.

Unless tile is acid-rated, strong acids may damage tile and grout. Sulfamic acid, however, is a milder acid that is most commonly used for tile and grout cleaning problems. It reportedly does not produce toxic fumes, damage. chrome or steel surfaces, bleach or burn grout. Sulfamic acid is available in powder form and mixed with water at a maximum concentration water of 6%. It can't be mixed any stronger. Thus, it is safe and recommended for MOST tile installations (not for natural stone like marble, limestone, or travertine). It is strong enough to dissolve efflorescence and mortar residue with damage to most ceramic or porcelain tile. Sulfamic acid dissolves hardened cement by converting the cement into soluble salts which can be removed with water. According to Aquamix, sulfamic acid is recommended for use on acid-resistant glazed tile or dense unglazed ceramic tile.

Note: Always test any DIY cleaning method first in inconspicuous area for ill effects. Always read and follow product label directions carefully.