A Tonsure in Time?

In the Singapore Teochew of my mother's generation, one way (perhaps the way) to express the idea of "suddenly, without warning" is to say bho da bho dak (using the Peng'im method of transliteration explained at the Gaginang.org website).

The English–Teochew dictionary at the same site gives the phrases bho seu bho siang (roughly translated, without much ado?) and bho gao bho dai (without advice or advance warning?) as equivalents for suddenly.

There are, in fact, many Teochew phrases with this bho ... bho ... structure, meaning "without ... without ...". For example, one can say bho tao bho bue (without head or tail) for something that doesn't make much sense.

The only problem is that my searches of the dictionary have not yielded any results for bho da bho dak. (This does not necessarily mean much.) For da, there are the interesting phrases gang da, meaning "only, just" and gao da, "as of now", but, in each case, no character is given for da, suggesting that it may be a purely colloquial expression with no Mandarin cognate.

Which brings me to my grand theory. I would love to think that bho da bho dak is really Malay botak-botak, meaning "bald". Admittedly, the Malay terms for suddenly have nothing to do with hairlessness, but are instead tiba-tiba (incorporating the notion of landing or arrival) or sekonyong-konyong. But wouldn't it be great if I could prove that the Singapore Teochews had fallen into this way of expressing suddenness, encouraged by the similarity of the phrasal structure bho ... bho ... to botak, which is surely among the first Malay words that any Singaporean Chinese child learns?

The sense development would not be hard to explain. In English, bald has the figurative meaning "undisguised, evident". To make a bald statement is to say something that has an all-too-salient, in-your-face quality about it.

It is surely not a great stretch to imagine that the same qualities of rudeness or lack of subtlety could be applied to a temporal adverb—with the basic image being, perhaps, a tonsure in time?