To be honest a good wok would be a better investment and as long as you don't fill it beyond half-way you would be fine. I have a deep fat fryer and it uses a huge amount of oil that is all well and good if you use it a lot but a shocking waste for the odd occasion.
Keep the bottle, paper coffee filter or piece of muslin and a funnel. No need to t grow the oil out.
That is something I would certainly recommend for a wok scenario but for a fryer like this it is a lot less practical. I grew up in a pub and our dff had a tap for draining which was great. Granted there are plenty of fryers out there and some may have a similar function for the right price.
Got a fryer almost identical and absolutely no reason not to keep the oil.
Maris Piper. Peel, chop chunky chip size and power boil for a few minutes, dry well and toss in some sunflower / veg. oil then straight onto an oven tray and into a hot oven until nice and crispy.