Have your septic guy 'stick' the tank 25% solids is the maximum safe level.
3-5 years is good rule of thumb
2 years is too soon unless you have a disposal in the sink or you put too much non degradable down the drain.
Filter for the washing machine.http://www.septicprotector.com/Productsandservices.html
The old systems on the Cape had leach tanks/pits 6-8 feet across by 6-8 feet deep
Yes there was a crew that would rejuvenate that pit by scrubbing it down...and the process did work...nasty work!
I guy in P'Town spent the summer in his 'underground house'....Yup an old leach pit....but it was decorated real nice!
There is a product that will temporarily rejuvenate the pit by breaking down the sludge that blocks the outflow.
I forget the name but the plumbing supply house would know what it was.
5 gallons of that stuff in the full, but failing, pit made it like new for about two months, enough to get the plans done and bids solicited.
Title 5 in MA now requires a leach field, rather than a pit, to better cleanse the effluent.
This requires more land and sometimes creative solutions.
There is a new type of 'honey wagon' that puts back some of your tank water to spike the tank, similar to how a sourdough bread starter is used.
Some people think it is a sham.http://www.bwseptic.com/environment.html
This link is broken, either the page no longer exists or there is some other issue like a typo.