It is important to your Company brand and image. You've spent a lot of time and money building your brand. Do you really want to send a bad impression to your customers that you are not concerned enough about safety to keep your equipment clean and free of pesticides and herbicides? If your clients see chemicals all over your equipment, they might worry that you are not concerned about their (the client's) family and home's safety.
It is important to the technician that the equipment is clean and chemical free. If there are pesticides and herbicdes all over the equipment, the techician will be exposed. The technician can pick up the chemical on clothes which then come in contact with the body.
As we have discussed previously, spray technicians wear PPE when applying chemicals; they do not always wear PPE when not applying chemicals. For example, a technician opening the lid on this sprayer (photo) has a good chance of touching chemical.
When cleaning your power spray equipment, the rinsate contains chemicals so use good judgement.