Condiments can really liven up a meal, but if you are using too much or the wrong ones, you can be unclean in a heartbeat.
Clean:
Mustards - the king on clean condiments. Check the ingredient list, but 99% of the commercially available mustards are clean with a capital C.
Vinegars ( balsamic, etc ) - clean
low sodium soy sauce - the lower the better - clean
Worcestershire - clean-ish. Look for the lowest sodium content you can find.
Dirty Birdies if you don't really watch the ingredient list!
Most ketchups - added sugar and salt. Try organic ketchups if you must; look for no salt added, no sugar added. Warning, these will not taste like that red stuff you used to smear on french fries - organic / natural ketchup is an aqcuired taste.
Mayonnaise - *sigh* My favorite. I love Hellmann's, but sadly, it does not love me back. Mayo itself is clean - veg oil and egg...Clean. However, the fat content just takes it off the menu. It's not right to eat whipped oil. :-(
BBQ sauce - most commercial sauces are essentially liquid sugar and salt. Avoid! Try a Carolina vinegar based BBQ sauce.
Some alternates to condiments:
lemon and lime juices - awesome on fish and vegetables
Try experimenting with a favorite seasoning mixed in a vinegar base. You might be surprised!
Salsa - again with the sodium content, but homemade or those refrigerated salsas can be surprisingly healthy.