as for the pump- the boost and water treatment will flush the pump- just be more concerned about that the fuel injectors themselves were cleaned.
If all that was done was that your gas tank was syphaned out, and the motor was not ran- then you should be good to go. Also, some times auto racers run a small amount of diesel in with a full tank ( i did 1/4 gallon to a full tank)- since diesel does burn hotter and takes longer to burn off. It cleans out the line, pump, and the injectors. I only did the diesel every 10,000 miles. after every 3,000 miles run the octane boost. keeps it all cleaner.
but no major damage will happen if a small amount of diesel was run through- but more then a half gallon will be trouble.
also- put in premium and add the bottle of boost to a full tank. you will not get the best milage-(for that tank)- but it will clean out your whole fuel line and tank.
yes walmart and even some gas stations sell the octane boost- get the highest number- a bit pricy, but it will defenitly assist your pump in getting any gunk out from the diesel.
have a safe road trip