Most manufacturers now recommends a deep cleaning every year. The Indoor unit does not bring fresh air into your home and all the dust, pollen, odors, cooking steam, candles, etc. gets trapped inside the machine.
When possible we will remove the plastic casting from the unit. Next we will spray the coil, blower wheel and drain pan with an approved based solution. Next we will use our battery operated pressure washer to flush everything out of the unit, some of the dirt will go outside and the rest will be collected in our plastic funnel. For the plastic casting and the filters, we will use a mild degreaser and wash all in a tub. It takes approx 45minutes to an hour per indoor unit.
As soon as we completed the deep clean you can turn your unit one and this will also help to dry out the unit.
You can absolutely watch and ask questions. It is actually encouraged.