With skill and some experience, a good reed knife or scraper can work wonders. A scraping knife is the most suitable for the actual fine work. Knives differ enormously in grinding, weight, handiness, and quality.
The knife steel quality is decisive for durability, sharpness and the possibility of who should regrind it. Cheap unalloyed steels are easy to grind but do not last very long. Refined steels are almost impossible for non-specialists to grind and should get resharpened professionally. This expense is worth it if you know a good knife sharpener! If necessary, ask your butcher or carpenter or send it to the supplier.
There are numerous reed options: one-sided grinding, two-sided grinding, hollow grinding, double grinding. For fine-tuning, and that's what most are concerned with, the so-called scraping knife is the most suitable. It should be heavy in the blade so that the weight of the knife is enough to scrape. It should have a single cut (one-sided) without a hollow slide. Our favorite scraping knives have a rounded tip. They allow you to scrape selectively just on a point as well as over the whole reed.
Left-handers need knives with the "back" grind. You should pay attention to it; otherwise, you will not get good results.
The blades of these knives are longer than 7 cm and can be very dangerous in the wrong hands. Especially with the rounded tip. In different regions/countries, you need a license if you take these knives out of the house. Always remember to never take them with you in your hand luggage. It will be confiscated-guaranteed!