Erm, there has never been a weedkiller on the market that only kills annual weeds and not other soft, greenleaved plants.
Weedkillers come in 3 different types - contact, where they shrivel the leaves of what they come in contact with, systemic through the green, where they penetrate the tissue of anything green but not woody and kill back to the root, or the path type weedkillers which kill everything and sit in the soil for a season or so to discourage new weeds from growing. None of these kill off woody based 'weeds' such as brambles, which require brushwood killers rather than straight weedkillers.
Weedol is still available, or glyphosate - spray or water on to the plants you don't want, avoiding the leaves of the ones you want to keep.

Thanks Bamboo. I fear I didn't explain the issue properly.

I've been gardening for forty years, and am well aware that weedkillers that deal with annual weeds will also adversely affect other plants. However, I have many annual weeds this year between a couple of hundred hostas.

For health reasons, I'm not up to using a hoe at the moment. I thought that one killer (? the original Weedol) worked on contact only. Thus, if, for example, an odd leaf of a hosta was slightly touched with the liquid when spraying weeds, it would not really threaten the life of the hosta, although that leaf might be burned.

Am I dreaming?

No, you're right - the odd splash on a leaf won't kill the entire plant. The one you're thinking of is now called Weedol 2 - granules you mix in water. Weedol now produces several weedkillers, but that's the nearest to the original.

Thanks for that Bamboo. I think I have a couple of boxes of Weedol 2: I will go and check! I had some notion in my mind that Weedol 2 was not quite as 'safe' as the original if spray went astray...

I usually use large quantities of glyphosate - before plants have come into leaf. Whatever else, the hostas are very much in leaf this year!

Thanks again.