Improved compositions and processes for removing photoresists, polymers, post etch residues, and post oxygen ashing residues from interconnect, wafer level packaging, and printed circuit board substrates are disclosed. One process comprises contacting such substrates with mixtures containing an effective amount of organic ammonium compound(s); from about 2 to about 20 weight percent of oxammonium compound(s); optionally organic solvent(s); and water.