I had a similar idea. Theres really no reason you couldn't have it; as long as it had a weaker effect than chem pistols.
That said, I do think throwing-only is viable. Max dex and throwing, get grenadier and three-pointer (and max the spec), TM for LTI mainly, and hypertoxicity/split spare (2 spec)/fatal throw (3 spec)/ripper. Throw knives between nade cooldowns, try to optimize your poison usage, so like use cave ear then other types.