I do not think it really matters but the drinkable DMSO is diluted (usually 70/30 water(distilled,no tap)
Ultra pure DMSO (99.98 % does not have a strong garlic smell as the other DMSO(99.9% which IS the INDUSTRIAL grade despite their bogus claims;this is why it is much cheaper too)
You can also buy the PET DMSO-it is 99.97% pure..
Notes: 1- do not use a formula that contains DMSO + herbs
2-MSM-beware most cheap MSM prices-their product comes directly from CHINA..