Haven't the mechanics for doing HP washing been removed a very long time ago (like, years ago)? It doesn't make sense anyway because as people have said, bosses can easily ignore your HP when doing attacks (and possibly 1HKO you).
readers, you're right, I just got a Halloween untradeable lvl 75 equalette that I scrolled with 70% three times and it has 22 int before the 9 int it adds if you wear the whole Halloween set, not to mention you can potential scroll the Halloween set, which is pretty much a free set because you can get one Halloween equip after farming 40 kaleido-spinning tickets from zombie elite pumpkins at taurospears. But it's no use to me to hp wash unless they keep the set as a give-away prize again next year, since I think it's the highest int set for a low lvl in the game. But the event is about to end so I might as well ignore my try.
You can only take out of MP if you've added to MP now.
Having extra INT doesn't increase your MP gain anymore. It hasn't for non-mages since Big Bang (2010) and it hasn't for mages since like 2011 or 2012.
It's absolutely USELESS to scroll for INT if you aren't a mage.
If you want more HP, I suggest spell tracing your armor. It gives HP to do that, plus you get some from starforce. That, combined with set effects (RA/gollux) will give you more than enough HP. And if it's still just not enough, get a decent HB neb and throw it on your pants. Costs about 300-700m depending which server you're in. And if that's just not enough after all of that, scroll an alt set of HP gear. No reason to waste a set scrolling for INT as a non-mage.
@littletlk: Int does affect MP gain, there's a few Phantom's who have MP washed to have 180-220k mp (useful for soloing Lotus, not much else) and the difference in MP between funded and unfunded Evans is quite large, I have like 275k MP while some other Evan's I know only have like 100k.