Does lightening the eyebrows invalidate Wudu' (ablution) or prevent water from reaching [the skin]?

Scholars have previously differed on the ruling concerning eyebrow bleaching (tashqir), with some permitting it and others prohibiting it, and the more cautious approach is to avoid it. Regarding purification, if the bleaching agent has a physical substance (jirm) that prevents water from reaching the eyebrows, then ablution (wudu') is not valid until it is removed. However, if its physical substance is gone and only its color remains, it does not affect ablution, because it is merely a change in color and not a layer that prevents water from reaching the skin, similar to henna. Sheikh Ibn Baz issued a fatwa stating that whatever has no physical substance does not prevent water, and whatever has a physical substance must be removed. Sheikh Al-Sudhan also stated that bleaching is merely a coloring and does not prevent water from reaching the skin or hair.