yes i am also having similar sprayer bottle, its quite handy 
yes try degreaser in foam lance bottle its very effective and fast, just u have to cover electrical parts by shoppers and after rinse off use high speed blower ( u can also disconnect battery terminals for saftey reasons )
Meguiars Hyper Dressing is my love now a days its very good product thats reason we sold out all and not left any small qty with us 
Its water base so dont leave stain so u have falexibility for use in enginebay in different ways.
a) u can apply by foam applicator pads and detailing brushes
b) spray in whole enginbay and then wipeoff
c) spray in whole enginebay and leave it to dry naturally ( since water base so it wont attarct dust )
d) spray in whole enginebay and after couple of mins rinse with water ( in case u like matt looks )
U can freely play around in case of non abrasive products like this Hyper dressing 