What is this thing?
I often advise people of this method, never gets a mention though,
I can personally vouch for this method on knotwood, used it and (touch wood) 4 years clear, but we use a different method on horsetail which involves crushing its stems with pliers and spraying it on the crushed parts with glyphosate (Roundup or similar). It is possible to weaken it by cutting it down as soon as it appears, but be prepared to consider this a very long term effort (could be 10 years plus before you’re ‘tail free). For a quicker result use the glyphosate which is a systemic weed killer that will penetrate deep into the plant’s root system. We crush the stems before applying because horsetail is bloody tough so spraying it without first crushing it won’t guarantee that the glyphosate will get into the plant.
Good luck, but my advice would be - don’t put the job off, it will get stronger and more established the longer you leave it. And if the stuff has spread to, or come from, a neighbour, you’ll have to consider it a joint task as it will come back if not treated wherever it is, so you’re not rid of it until your neighbours are too.