I used undergravel filters for years. Decades. They do a good job. Just be aware that if they are not maintained, they can be a Nitrate nightmare. After a few Nitrate failures, I started vacuuming the substrate to remove waste. I also went to the hardware store and found some PVC reducers so that I could connect a drain hose to the riser tubes...I would do a water change like this once or twice a year to clean out the plenum underneath the gravel. Other than that, it was mostly smooth sailing. So, to recap, just do partial weekly water changes as normal using a vacuum tool similar to Tetra Hydro Clean or some variation to drain your normal percentage of water. Then, once or twice a year, connect to the riser tubes and do your PWCs that way. But, overall, undergravel filters have a lot of science behind them and work well.
I have also heard that EHEIM has a reverse flow Undergravel Filter that pushes the waste into the water column so that a HOB or canister filter can remove the waste.
Hope this helps