Well you CAN eat it and it WILL get into your system, but it's a huge waste. First, heroin is metabolized extremely extensively in the liver which makes it less lipophilic = less BBB permittivity. The whole point of heroin is that its more lipophilic than morphine, heroin itself is not active as a drug, only its metabolites. So you want it metabolized as close to the brain as possible, which means eating is really counter-productive as first-pass metabolism which other ROAs avoid is going to tear it apart. So with oral administration it is pretty much the same as morphine, which still works orally.
Second, if you've been an IV user of heroin then you will be extremely underwhelmed by oral administration. Compared to IV there's no rush, the high is less intense (albeit longer!). Third, assuming you have tolerance, you will need a lot more to get off. People choose IV over snort/smoke out of economical reasons, oral administration is WAY less economical than even smoking it.
So bottom line is, you can do it. Go ahead and try, but I'll bet my middle nut that you won't do it again.
Given, oral administration is probably the healthiest and I personally prefer it to other ROAs. I take my drugs orally, but luckily they're either not much worse orally or even better (codeine, which actually needs first-pass in order to work). But even I wouldn't eat heroin.
E: I just realized how anti-HR my post is recommending more harmful ROAs, but still. It's just reality with heroin.
