Some lips on Bin Chicken are constructed from the red dirt, and as such are susceptible to becoming "fluffy" over time. As such, they should be re-compacted periodically.
The process is similar to that which is used for surfaces on the Dirt Jumps (that is described in another post). Given that these are smaller lips, it may be possible to simply: (i) soak the surface at the end of the day; (ii) allow the water to penetrate overnight; and (iii) the following morning work the surface with a plate compactor.
The objective is to retain the existing shape, and leave a smooth compact surface.
In some cases, after an initial compaction, the usual process of wetting and brushing with fines may be used to achieve a better result (optionally with a further round of compaction, if moisture content allows).
As always: (i) take your time; (ii) finish what you start; and (iii) have pride in your work. The goal always to strive for the original as-built condition, never to modify or change. Preparation is always key, along with ensuring you have the time and patience to see a job through to the end. Quick fixes never last.