Use a foam paint brush or a sponge and just apply it to all the grout lines.  

I prefer not having to do the actual physical work, but have many times ended up with a hammer, paintbrush or floor sander in my hands, because a carpenter disappeared off the job or something. 

Some of them never lift a hammer or pick up a paint brush - they just lead the project.

I have everything that I feel a rehab that I would feel comfortable working on myself would need (multiple sizes of philips, flatheads, wrenches, hammers, power drills, adhesive guns, paintbrushes, sanders, pruners, etc.)

This way the only weapon needed to win the battle is a paint brush and a gallon of the matching color. 

Or should I just throw in my paint brushes and rollers and hire this out to professionals? 

*If someone asks how much the deposit is, asks for a reduction in the deposit/rent or if they want to work out a payment plan on the deposit then they will probably not be the best of tenants*Dollartree is great for cleaning supplies, soft pretzels and paint brushes; you will want copper sponges for baked on filth and magic erasers for kids' artwork at minimum (Make sure to run the pretzel under water before adding the salt or cinnamon sugar then put it in the microwave)*A crescent wrench can be used as a meter key in a pinch*The better than wax toilet seals are less messy than wax and toilet bolts usually require a sawzaw to remove; Flappers come in two sizes: 2" and 3"*Sharkbites and pex make plumbing at least 100 times easier *Drill augers work pretty well to clear drains and bathroom sink drains can sometimes be cleared with a screw slid around the stopper to remove hair*Thinset also works as grout and caulk also works as mastic in a pinch* A garden hose cap or shutoff will resolve a leaky hose bib for right now; Can't pressure wash without a hose bib?

How a person employs the tools tells you how their brain views it's possibilities.If I gave you a paint brush could you give me Starry Night?

My wife turned to me and said “ for 3k give me a paintbrush”.

Think about things like property lien searches, inspecting property with tenants in it and reporting findings to the investor, checking on zoning ordinances, advertising for purchases, negotiating with the Sellers, scouting the best financing terms, and other such things.Anyone can swing a hammer or sling a paint brush.