I  provide a pump dispenser of soap/body wash in each shower.

Potential tenants pay attention to kitchens -- the appliances (if you have room for a double door fridge with a water dispenser -- that is not typically found in a rental and will be memorable), interesting lighting that makes the kitchen bright, and a fancy counter (it doesn't need to be stone, I've purchased the "stone looking" cheap counters at Lowe's and it worked just fine but for my higher end rentals I use real stone.  

Taking the cash flow and moving into the next property means your cash flow will have a 1 to 5 relationship with the PV...and because that positive CF continues each month/year, that "pez dispenser" of cash allows you to continue to move it forward on that 1 to 5 relationship with future PV's.

Anybody mounting refillable dispensers and filling them with bulk gallons of shampoo, conditioner, etc?

Shampoo and Soap dispensers in the showers.  

Bear toilet paper dispensers.

I'm sure you will have the opportunity to dispense information as well as assimulate.

Use wallpaper, unique furniture, candy/cereal dispensers in the kitchen, bright colors, definitely add that game room, etc.

I have a financial plan to purchase a duplex each for my children when they turn 5 years old, hopefully have the property paid off when they turn 20, and dispense all Cashflow from the properties into their personal accounts monthly.

More than covers the utilities.Been a few years... only two complaints - coin box was full and wouldn't take more quarters and a bent quarter being stuck- slid right out.We picked up a change dispenser when Covid hit and installed it in the wall... now I just collect bills and move quarters back and forth.Some people swear by using a credit card service for convenience and to make sure they don't make a mistake in reporting to the IRS.