Glimpse.org seems to think so.
And I don't disagree.
The first wedding I went to in Israel was for the son of a friend of mine. I went in full suit and tie -- and I think I was the only person (aside from the groom) who was that dressed up. Yes, I think you could walk in off the street and be treated pretty well at an Israeli wedding. And Israelis, for the most part, don't care too much about breaches of protocol.
This video seems to have a slightly different philosophical bent than everyone's favorite Owen Wilson and Vince Vaughn comedy, Wedding Crashers. (For one thing, it looked at the question somewhat more realistically.) Yes, Wedding Crashers is correct: Almost anyone can crash a wedding.
But whereas the stars of Wedding Crashers went all out and made toasts, to embrace the bridge and groom, and to become the center of attention, Glimpse advises more modesty. They're probably right.
But they agree on the important stuff. A crashed wedding means: Lots of free food, lots of dancing, lots of horny single people. (Although, you're not going to meet anybody at an Orthodox Jewish wedding if the dancing and dinner is separate. Crash the less religious weddings in Israel for that.)