YES this can be used and you can get some from pharmacy. It can also be used to try and releive some other precipitates. I am referring to its use in CVCs of course not PIVS...and yes you can give lipids in a peripheral vein if needed.
This is what we do with TPN and lipids and we rarely have problems with lipid build up.
When you disconnect the completed infusion you should flush the lumen with 10-20 ml normal saline in a good pulsatile push pause method. Many nurses want to just take down the lipids and hook up the new bag but it is much better to perform the flush.
i would be leary of using ethanol in vascular access devices nowadays as some are made from polyurethane and ethanol degrades polyurethane. below is a link to a commonly used port from bard that discusses this issue. powerpiccs are also made from polyurethane.
however, other piccs are made from silicone (per-q-cath picc) and ethanol is not a problem. you might want to check with the literature for the product first.