Many years back, Bush in the UK produced a colour decoder which was
'revolutionary' compared to other manufacturers' efforts, in that the
subcarrier was regenerated in the decoder directly from the burst, rather
than being a free-running oscillator just locked to the burst with a PLL.
They did this by deriving a phase-adjustable pulse from the H-flyback, and
using this to 'notch out' the burst from the back porch period. The 10
cycles of burst thus recovered, were then applied directly to the 4.43MHz
crystal, which caused it to ring at exactly the same frequency and in
exactly the same phase as the original subcarrier. Always seemed to work
pretty well, and they continued to use this system over a period of
probably 10 years or more, covering three chassis designs / revisions.

This was first done by GE, circa 1966, in the Portacolor set, mostly because
it was cheaper.

Another way of looking at this system is that the crystal was an extremely
narrow-band filter that removed the "Fourier sidebands" around the
subcarrier frequency created by transmitting the 10-cycle burst only once on
each scanning line.