My sump is just that, not a refugeum, just a place to hold other equipment. no rock, sand, etc. 1st, I have a sump monster... a 2" rock crab that lives in there, helping break up whatever gets in there. 2nd, yeah, once a year, I disconnect everything, pull the sump, and clean it thoroughly. In my case, that's not that hard. EShopps RS100, drains and returns all have unions, external pump with a union ball valve on inlet and outlet... Just not that big of a deal.
Clean the sump, clean the pumps, scrub the skimmer body, inspect _everything_... good for another year. Takes me about a day.