Generally with any spider which lives in houses and gardens, it doesn't really matter where you put the spiders or what you do with them, others will move back in from the surrounding area fairly soon, even if you don't see them.
The media have gone mad about 'false widows'. There are (and have long been) a number of false widow spider species in this country, three of which are associated with houses and gardens. One of these in particular, Steatoda bipunctata, has been common and widespread throughout the whole country for as long as anyone has recorded spiders and is completely harmless to humans. The 'fasle widow' the media mean is the so called 'noble false widow'.