I think isopropyl alcohol contains, even in its purest forms, a high water content. This means repeated use on metal fittings will eventually cause pitting, corrosion, or flaking of the metal.
I personally use Golden Grain (Evercleer) but have also used Vodka.
Vodka which is normally 80 proof is 60% water.
Isopropyl is generally sold at 70% minimum, which is 30% water. You can usually find it around 90% in most pharmacies which is 10% water.
I use isopropyl on everything but cartomizers, which I boil in water. As long as you let it dry out, there is nothing toxic left behind. Since cartos absorb liquid by design, that's why I don't use isopropyl on them. I also keep Everclear (90% Ethanol on hand)
Keep in mind Ethanol is a poison just as isopropyl alcohol. People seem to forget that since so many of us commonly ingest small amounts of Ethanol frequently. The very small amount of Ethanol or isopropyl that you may possibly expose yourself to is far to little to cause any problems.