Ban someone else by suggesting their websites?
You're welcome to try it. It's been tried before. It hasn't been tried often.
Why not? Well, it's a very stupid thing to try to do, because the ODP process is implemented by humans who might see through simpleminded strategies. Well, that probably doesn't stop a lot of spammers.
And it's a very risky thing to do, because there's no predicting how humans would react to irritation (some scratch the itch, some ignore it, some start looking for a cure for mosquitoes). Well, that probably doesn't stop all that many spammers either.
But there's a psychological barrier. To be a spammer you have to believe doing an irritating thing over and over again is the key to success. But if you have that attitude, it's hard not to think that suggesting a site over and over again isn't simply the way to getting it listed. And ... you might be right. A site MIGHT get listed before the volunteers are goaded into investigating the submittal abuse! For all you know, a site might get listed WHILE the volunteers were investigating the submittal abuse.
Focusing on what happens to a site suggestion is always a mistake. A site suggestion is a throwaway note about where one might find a relevant website--nothing more. What matters is the website.
What gets a site listed is the website, not a particular procedure suggesting it.
What usually keeps a site from being listed is the site itself, not a failure to use the right suggestion method.
Because editors are not site suggestion processors. We're website reviewers. And that's a completely different thing.