I agree with you veg, I think they're pretty indestructible... and probably by cutting yours back severely you're signalling to the plant "Oh he likes me, here we go again, youthfulness reborn!" and strong fresh growth emerges at speed! I mistreat mine every year (not quite as severely as you!) - and they must be 10 years old now - and they never fail to give more fruit than I can pick (because picking IS a fairly painful exercise...). If you really want to destroy it without digging it up, cut the main stems low and parallel to the ground, drill/dig a hole in the stems to make a little hollow/cup and put in some creosote or similar (and the poor bush will think "Oh he doesn't like me after all!" and give up.) But before you do that I want to sing the praises of the 'umble gooseberry. I don't know what type of gooseberry you have but if it's the hard green sort try doing things with 'em BEFORE they fully ripen (i.e. when still hard and frankly very tart/sour and quite inedible until processed in some way...) There's loads of recipes on the Net - I don't aspire to much beyond the 'umble crumble myself - but they're delicious. And what's even better they're EARLY... one of the first fruits (e.g. before red/white/blackcurrants). Those of a gourmet nature can make inspiring relishes to accompany fish or whatever. And wine of course, chutneys, jams etc etc. I always think the automatic association with "gooseberry fool" has done the gooseberry a mis-service, it's a dependable servant (but get it early!)
Incidentally Piglet's ace layering technique can be used on other "soft" fruit bushes and vines; it even works with fig trees (don't know about one in a pot but a more substantial figtree will usually have branches brushing the ground...). Raspberries of course effectively do it for themselves (and come up in the most unhelpful of places

).
bb