Anderson's comments followed last week's revelation that 2007 Geelong premiership player Mathew Stokes had been charged by police with one count of possession and one count of trafficking cocaine.
The Cats confirmed a raft of penalties for Stokes on Monday afternoon, which were later supported by Anderson, though the small forward must reappear in court on March 12.
With more than 700 players on AFL lists in 2010 and with that number set to grow with the introduction of Gold Coast and Greater Western Sydney, Anderson said the AFL would continue to look at ways of improving its procedures.
He added achieving a clean slate among every player was almost impossible.
"The reality is that what we're trying to do is make progress," Anderson said. "What the education and illicit drugs policy has done over the last four years has seen the number of positive tests drop below one per cent in the AFL competition for the first time.
"It's less than a quarter of what it was before the illicit drugs policy and that education program started.
"We know that there are still players who use drugs and that'll remain a focus to try and eliminate, but there has been a major reduction in that and we know that for a fact from the testing and education we do."
Anderson the said the next round of testing results would be made public, although a date has yet to be confirmed.
Anderson backed the AFL against any organisation in regards to how it deals with the issue of illicit drugs.
"I'm not sure there is anyone [or] anywhere that I'm aware of [that] does as much education around the issue of drugs as much as we do," he said.
"I don't think there is any excuse really for a player these days not to understand what the rules are because it's hard to imagine a more robust education program that has been provided.
"Yes, we will look to ways of doing it better. The fact that one or two or however many examples of transgression - I don't think should be used to say that an education program is not worthwhile."
Anderson said Geelong had been regularly updating the AFL about the Stokes issue.
