What's the most efficient way to get (rid of) experience?

So, there I was, farming xp from my skeleton farm, getting myself set up with a set of enchanted tools, weapons, and armor, preparing for an excursion into the Nether. After ending up with a second helmet with Aqua Affinity and a bow with Flames (so useful in the Nether), faced with the prospect of punching another couple of hundred skeletons, I became weary. I still had two bows left to enchant! But I couldn't face it. I figured, what's the harm? I'll just give myself a little boost out of this tedious rut.

So I fired up console commands, not entirely sure what they did. I figured why not mess around with it? There's even a help page, this can't be so difficult. So I found the xp command:

xp <amount> [playername]
xp <amount>L [playername]

Hmm. Let's try this:

xp 10 mikeTheLiar

Oh. Well that only bumped me up about half a level. How about this?

xp 5000 mikeTheLiar

Sweet! 120 some odd experience levels! Let's get enchanting! Now fully equipped, I had a good deal of illicit xp that just didn't feel right keeping. How can I get rid of it?

xp -5000 mikeTheLiar

Hmm. "Can't give negative experience." Wait, wasn't there another command? I wonder what that does?

xp 5000L mikeTheLiar

NOOOOOOO!

I didn't want this. No, not like this, I didn't want to win like this! Anyway, so now I have several thousands levels of unwanted, ill-gotten, dirty experience, and on top of that, it's completely broken the game for me. I just didn't want to have to spend another 20 minutes farming, not render my farm obsolete (after all, I spent a good deal of time and effort building the thing).

How can I get rid of the evidence, without turning all of my materials into tools/weapons/armor, enchanting them all, and then throwing the result into a lava pit? Is there a command to get rid of it? Is there a tool like MCEdit that will get the job done? The only thing I can think of is killing myself, but I'm deep in the bowels of Hell right now, and I'd rather not have to lose all of my sweet, newly enchanted equipment. I could just wait until I get home, but then I'm losing all of the xp that I'm honestly earning killing Blazes and Ghasts right now.

/xp -5000000L mikeTheLiar

The xp command does not work with negative experience points, but works for negative levels, according to the Minecraft Wiki.

You can just /kill yourself.

You will probably want to learn how to use the /tp console command to go home so you can drop things off first though, to avoid losing equipment. (I always found the lack of built in warping to be unsatisfying.)