Bonide Fruit Tree Spray Concentrate is labeled to be applied to flowers, Canna Lillies not excluded. You want to mix 1.5 oz per gallon water to treat plum trees, grapes, and Canna Lillies. Please see the product label for complete application instructions.
Bonide Fruit Tree Spray Concentrate is not labeled for use on pear trees. If you could give us more information on what you need to treat for, we would be happy to recommend a different product.
Per the label you should only apply twice a year with the Bonide Fruit Tree Spray Concentrate. We do apologize for any confusion and have updated the incorrect Q&A you saw.
We would not recommend spraying Bonide Fruit Tree Spray Concentrate when bees are actively foraging. It should be fine once the product has dried completely. Keep in mind that this is an insecticide, as well as a miticide, fungicide, aphicide, and scalicide all in one. It does have the potential to harm beneficial creatures.
The proper technique for cleaning out a sprayer no matter what product is used would be the triple rinse. No special soaps or cleaning chemicals are needed. Simply put clean water in the tank, shake it well, pump the clean water through the nozzle some, dump out the remaining water, and repeat 2 more times. You can also use a Spray Tank Cleaner if you are using the same equipment for multiple kinds of products.
You should be sure to shake the sprayer occasionally or agitate to keep spray particles of Bonide Fruit Tree Spray in suspension during application. This would help prevent or reduce a buildup inside the tank. Use clean water in a triple rinse method. You could also use a tank cleaner like the Prime Source Tank Cleaner Select