Hi CarolP,
Thank you for sharing your feedback on the TrueCoat 360 handheld airless sprayer. We're not sure where you saw this information as the startup procedures on pages 22-23 of the manual don't mention the need to mineral spirits as part of flushing out any remaining storage fluid in the sprayer from our manufacturing testing process – only water is needed.
For short videos and helpful tips to get the most our of your sprayer, please visit our Education Center on Graco.com: https://www.graco.com/us/en/homeowner/support/education-center.html.
- JW