I used to have the interrupter issue - but since I'm an extrovert, I never found it particularly difficult to address with people. Generally I was polite or cordial, but I can think of one case where I pretty much (as professionally as possible) tore someone a new one.
My last role was more support oriented, so I would routinely engage with the design engineers who were building spec packages that I used to purchase project materials. I was regularly supporting 50+ orders at a time, and I was the only one doing that job, so could sometimes be a bottleneck.
In this case, I had been waiting for technical feedback from engineering, and was sending them a weekly e-mail to find out if they were ready to proceed. It had been several weeks and they hadn't responded to a single e-mail. I ended up getting sick and was out of the office for a couple of days. The day that I got back, about 5 minutes after I got to work, this guy storms into my cube and starts yelling at me. I have no idea who this person is, but he looks exactly like Wormser from Revenge of the Nerds.
My first thought was "who the fuck is this Wormser-looking-asshole, and why is he in my cube?"
He rants for about 3 or 4 minutes straight, while i just sat there and looked at him. As soon as he paused to take a breath, I was like,
"Oh, you're done? Good."
"Step 1, back up and get out of my cube.
Step 2, knock and wait for me to respond
Step 3.... why are you standing in my cube? I didn't invite you in, back up.
Step 3, wait for me to acknowledge your knock
Step 4 introduce yourself and tell me why you are here. Something like "Hi, my name is _______, do you have a minute to talk about ____?"
Seriously, why are you standing in my cube trying to catch flies? I've asked you to back up 2x already -I assume you understand that
Step 5 If I agree to talk, wait for me to invite you in. If I tell you I'm busy, then set up a meeting for a later time.
Just a few tips for you as well - if you want someone to do something, you need to ask respectfully. Getting in a stranger's personal space and yelling at them is only going to get you dragged to HR. You also need to give people adequate time to respond. I've been out sick - but you haven't responded to any of the e-mails that i sent in the last month. Coming into my cube and yelling less than 24 hours after sending me something isn't going to get you results.
Now, would you like to try this again, or would you like to just go back to your desk and pout?"
I was proud of myself for not making any revenge of the nerds jokes and not giving him an atomic wedgie. The people that sat around me were trying (unsuccessfully) not to laugh.