A client recently reported that he has clogged his prep sink and asked for advice. Personally, I find clogs to be rare if you use your garbage disposal properly while running water through it. The only time I ever clogged a pipe myself was in an apartment after putting potato peels down a disposal. I learned my lesson!
Here is a primer on how you can try to first avoid, and then repair, this potential problem.
1) Make sure that the garbage disposal gets run every time anything is put down it. Run it with water. If there is a lot of waste going down it, run the disposal with water running for 30 seconds after the disposal sounds like the debris is cleared.
2) If you do clog the drain, one way to try to "force" the issue is to fill the sink up with water, pull the drain plug, run the disposal, and the disposal will "push" the debris through by force because it will be pushing the water out.
There is a risk: that you end up with the sink full of water and a clog so severe that it does not clear out with that force. The other risk is that if there is a dishwasher air gap or a double sink, you will actually force water backwards up into the other sink or out through the air gap. If this happens, it is an indication that the clog is beyond the P-trap and in the main line of the drain.
If the sink remains full of water, take a container and scoop out the water and get rid of it through another sink so that the next step gets easier for you.
3) Disassemble the P-trap under the sink and clear it out. That can be done without tools, usually you can do it by hand because they are plastic fittings. Pay attention to how it comes apart and put it together exactly the same again. Place a bucket underneath as you disassemble it so that no water spills into the cabinet. Wear long rubber gloves if you are going to get grossed out about getting a little dirty water/debris on you.
After doing this, you should be able to visually see whether the trap or pipe is clogged. Look at the inside of the P-trap. Is it full of debris? Is gunk caked onto the sides of it? Clean it out. Look where the drain pipes continue toward the wall, usually a horizontal run before it goes to the wall into a vertical drain. Is that clogged with gunk or debris? Clean it out. If the P-trap and the adjacent run of pipe are not the culprit, then move on to part 4.
4) Use a drain snake to clean out the pipe. If you don't own one, you can buy one or rent one from a home center, lumber yard, or supply house. You can also call a plumber at this point if it is beyond your skills or your gag reflex!
Good luck. Please respond with any additional tricks, tips, or questions that I can answer.