Water / oil 'gunge' build up can be minimised by installing a substantial wall-mounted water filter / lubricator / regulator (Part no. 3638).
The supply of air to air tools should be through a separate regulator to that of your underpinner.
Connections should always be made through quick release fittings. Airlines must not trail across workshop floors, by law.
All our airline fittings are to 'PCL' pattern. Tails to match Q/R bodies.