Error while compiling EntityCleanup: The type 'System.Collections.Generic.HashSet<string>' cannot be used as type parameter 'T' in the generic type or method 'Pool.Free<T>(ref T)'. There is no implicit reference conversion from 'System.Collections.Generic.HashSet<string>' to 'Facepunch.Pool.IPooled'. | Line: 209, Pos: 22

following 

line 184 should be

                entityList = Pool.Get<List<BaseNetworkable>>();

and 207 and 209 should be (you can remove line 208)

				Pool.FreeUnmanaged(ref entityList);
				Pool.FreeUnmanaged(ref deployables);

Thank you

Merged post

Confirming @firingLaserz post, that his code is perfect and the plugin is now working.  Still would like to see an offical update for all of those servers that are unaware of the situation.