Got a plumber in there, and he took out a 3" piece of wax from the pipe... he said it was likely hair gel.

Several Airbnb superhosts suggested Zinus Memory Foam Mattresses (https://amzn.to/2CIwFH9) and Luxury Plush Gel Pillows (https://amzn.to/2oXLzzh).

$15.00 per closetLight fixtures – glass cleaned and bulbs replaced $15.00 per fixture /$1.00 per bulbCeiling fan, blades- clean top & bottom, motor housing dust free $30.00 -$50.00Vacuum – per room (carpet is shampooed by management after move out at no charge) $15.00Carpet- burns, stains, soil as per estimate / replacementBaseboards – dust, wipe off, vacuum per room $15.00 per roomA/C vent cover – vacuum, dust $15.00Windows – Glass, tracks, clean and dust free $20.00 per windowTo remove window pane, slide pane to center of track- grasp each side, gently lift up and pull forward to remove, clean, replace in correct order.Window- Glass replacement $35.00 per windowScreens replacement- $25.00 per window -$40.00 per patio door $25.00- $40.00Mini-blinds replacement $20.00 per windowPatio door – Glass, clean both sides, track vacuumed, wiped clean $35.00Patio blind replacement $50.00 per windowOutdoor patio globe- clean $15.00Sweep off patio and railings $15.00Bathroom exhausts fan/vent cover, clean, dust free $15.00Bathtub, clean tub and tile surround $25.00 – $60.00Bath sink, vanity/countertop, clean $20.00Bath – medicine cabinet, clean inside, mirrors, light guard $20.00 minBathroom floor & wall tile – wash, clean tile $20.00 minTowel bar replacement $18.00 minToilet tissue spindle replacement $5.00Toilet – clean inside bowl and outside $20.00 minToilet seat replacement $20.00Kitchen cabinets – wipe off grease; remove shelf paper, empty out $20.00 minKitchen-sink, countertop, wipe off, clean garbage disposal ring $20.00 minDishwasher – clean, remove any food particles from inside $20.00 min Vent hood – wipe off grease, clean filter, clean light guard, top/underside $20.00 minStove/ Oven- wipe off exterior, clean under drip pans, clean oven/racks $25.00 min to $125.00Drip pans – clean (replacement cost is $7.50 each) $30.00 maxBroiler pan replacement $20.00Refrigerator/ Freezer-wash off exterior, top, seals, inside, crispers $20.00 min to $75.00Walls / Woodwork – remove nails, screws $15.00 minWallpaper boarders-removal per room $50.00 minNicotine – stained walls/ woodwork that require cleaning (see below explanation) $25.00 per hour min.The cost to prep the unit for painting requires the walls and woodwork to be washed clean from the smoke odor/ and nicotine stained damage.GaragesGarages should be swept clean and all debris removed.

Once they aren't attracting roaches inside the units, get a pro out to spray, plant gels, and traps.

So, I didn't have to take any major steps to remedy the issue, but I am interested to hear others' tips.My real estate agent said that there is some chemical that you can put on the walls and literally watch the nicotine run out of the walls (don't recall the name).

We use those aerosol smoke bombs from the janitorial supply that neutralize "fire smoke smell" which is harder to eliminate that nicotine .They're not expensive .. two or three cans in one small room , close it all up for at least two days.

@Julie Groth, I use a 1.5 inch gel foam topper from Kohl’s.

Many will pitch their own market, and while technically I am not an exception to the rule, I would say if you are looking into long distance investing just make sure that you gel really well with whomever you are considering working with to acquire and manage the assets.  

@Brynden Noble you many want to have your tech check the air filter and for nicotine stains on the bathroom fans.

One cheaper/quicker option to update the kitchen instead of paint might be to use a gel stain on the cabinets to give them a darker, more contemporary look.