There are now on the market small, portable pressure washers meant for outdoor sports. Those are typically powered by batteries and have a water tank, to be used without a water supply and electricity. To give some names (no endorsement): Bosch Fontus, Kärcher OC3. Those are very convenient to quickly remove mud and dirt at trail heads, or in the street for those living in cities.
They are operating at much lower pressures than conventional pressure washers (5-20 bars vs 100-200 bars). But the beam is highly concentrated, and is shaped like the one of a high-pressure washer.
There have been already questions about washing bikes with high-pressure and garden hoses. But the question here is when using such washers, should they be handled as high-pressure washers, or is the pressure not high enough to cause the typical "damage" linked to high-pressure washers (damaging the bearings by washing out the grease)?