Ok, so im closing in on 80 slayer, and ive heard before that chinning nechs is pretty good, and that you can maybe profit? Can anyone confirm this, and if so, either point me to a place to find out how or just tell me? Much appreciated

You probably won't make profit with rune boots at such a low price. Decent range exp and crim charms though.

before free trade, rune boots were over 200kl ea, now they are currently 22k ea. since rune boots were the drops that were making you profit, it is highly unlikely that you will profit. however, nechs are a decent source of crimson charms and their seeds do add up to a decent price. you will still not profit but it will cost alot less than some other chinning methods

The primary source of profit is from yaking infernal ashes, not the rune boots.

I feel like (but don't have hard numbers to show, maybe I'll test next task) that if you bring urns for the infernal/accursed ashes, and count the prayer xp as worth whatever gp/xp prayer is (currently at about 14 gp/xp for dragon bones on altar, more for frosts and ashes, and you might even add a little more since you are barely spending extra time getting prayer xp this way), you do profit. Since you are 70 prayer, supposing you'd eventually go for 95, this may be worth considering.