that's one angry Gibbon! I googled 'gibbon' and most are them look rather bored like this delightful couple
Gibbon won't dislodge anything, it is perfectly safe at any mileage - in my own opinion - because it does nothing else but circulate the oil the exact way it does at any moment the engine is running.
Btw, why was this called gibbon method
Here's my take on Gibbon vs 'drain and refill'
- replaces all fluid at once if needed OR
can be used to replace any amount of fluid at once (just like the drain and refill method). It is a little risky on the hose o-rings and clip but these can be replaced and once new can be reused multiple times
- no need to jack the car and slide underneath - no such mess as dripping oil on the garage floor
- it takes 13-15L to completely replace the old fluid in one step or can be used to replace any exact amount of oil at once - 1,2,3,4,5,6,7 liters and so on
Drain and refill
- the only way to clean and inspect metal particles stuck on the magnetic drain plug
- car is safely jacked with jack stands (hopefully no owner will slide underneath a car lifted on the spare jack), the pan plug comes out, oil is drained in a pan, messy, plug goes back in, transmission is refilled and engine runs for a while, then either same day or weeks later the car is jacked again, plug out and repeat the whole thing.