Expungement Sealing
Generally if you want a clean record you want expungement.
I am not a lawyer but I have studied the laws concerning this. If you "seal the record" your criminal record will show some vague info such as the case # and specify that the case has been sealed; which is not really 'cleaning' your record.
An expunge is designed to act as a way of returning the person's standing to being such that he was before the item appeared on his record, and an expunge is desirable.
But before we get there let me clarify something, there are 2 types of records! In fact numerous agencies hold their own records and completely deleting this may be impossible, though at least you can probably get your employers from seeing the record, two most common agencies that hold this record you speak of is the:
1.) District Court. "Criminal Justice Record"
2.) State-wide police agency. "Law Enforcement Record"
3.) FBI & etc.
And there are two different sets of rules and procedures about how to go about to sealing or expunging these records. Which records an employer would check depends on how meticulously they do their homework, and I would *guess* that it is the "Law Enforcement Record."
That is good because you cannot expunge/delete a District Court record. Period; and getting a seal on it is not easy either.
In order to expunge/delete the "Law Enforcement Record" you must wait 3 years after since the date of arrest. If you were convicted (found guilty) or your case was dismissed, you must get the court to "vacate your conviction" before you can expunge this record.
These are the laws in Washington, hopefully this gives a perspective.
EDIT: BTW, check your record and see if it contains anything, you cant do much with your District record since sealing will still leave a glaring "RECORD SEALED" which isn't really helpful. Although some local police agencies may not file a record at all! They are generally require a fingerprint to file a record; if you were arrested and fingerprinted, then you probably got a record.
Don't take what I said too seriously; I am not a lawyer and maybe there are other ways out, feel free to do your own research or talk to a lawyer.