I just did some searching. Thorne has a form of sustained release Glutathione which they claim bypasses the gastric destruction. Does this sound plausible?
Here is a quote from their site:

A common mistaken belief is that glutathione is not well absorbed when it's taken orally, but significant data confirms it is efficiently absorbed across the intestinal epithelium by a specific uptake system.*

Glutathione-SR from Thorne Research represents an important breakthrough in glutathione supplementation. Absorption of oral glutathione can be affected by stomach acid or enzymes in the duodenum, which can break glutathione into its amino acid components. However, the sustained-release properties of Thorne Research's Glutathione-SR protect it from stomach acid and digestive enzymes, allowing slower release and a more steady level in the blood of this essential nutrient.*