THEY may be wrinkled, toothless and economically conservative to say the least, but Hanoi's grandmothers could prove to be the new financial foot-soldiers in Vietnam's recovery. As growth slows and new foreign investment flows stagnate, Communist Party propagandists have launched a drive to exploit the vast untapped reserves of dollars, gold and jewels hidden in family homes. Traditionally it is a hard-bitten, housebound grandma that has the task of looking after the haul deep within the darkened back rooms of Hanoi's narrow and pokey homes. A decade of growth and reform has done little to erode the tradition and Vietnam's official savings rate is widely estimated to be among the lowest in the region. Given what it says about the state system, Hanoians' long mistrust of banks and conspicuous wealth is rarely officially discussed other than in the most oblique calls to 'mobilise domestic capital'. This week it was different as the official Thuong Mai paper launched the campaign with a stirring commentary. Urging people to be 'glad' with official calls from party chief Le Kha Phieu to follow the lead of Vietnam's thrifty confucian forefathers and save, it warned that the mattress was no longer the best place to do it. 'But what are we talking about when we mention the term 'savings'?' it asked. 'Is it the act of putting cash into the moneybox like the little schoolgirl is doing? 'Hiding the money under the rafters of the kitchen? Or hiding it at the bottom of a trunk? Acting this way is good, but outdated. 'This money is ours, it is the money of our people, and it is being wasted away . . . the duty of each individual is to bring out this capital, even if it is not a lot, in order to develop the Homeland.' Intriguingly, the paper claims the amount stashed in homes across the nation could be as high as US$6 billion - more than double the estimates of even the most optimistic foreign banker who has long eyed 'Grandma's Gold' with envy. Like classic great propaganda drives, the picture is more clouded than suggested. Decades of war, hard-line party rule and hyper-inflation may have ended but Hanoians talk of new suspicions as they continue to squirrel the cash away. An over-valued dong, a more efficient tax-man and a shaky semi-private banking system are all cited as reasons to keep the money home. 'In Hanoi, you can trust only your family,' said Mai, a 27-year-old worker in a foreign bank who keeps only a token amount invested with her company. 'History has taught us that. It will be a hard habit to change.' Dip into Hanoi's frenzied street-side commerce and markets, and it is easy to get a feel for the pulse of the black economy. Steel brief-cases with attached handcuffs are sought after by traders of a certain class while the city's goldsmiths talk of frequently being asked to deal with French-era gold bullion. Regular shoppers get used to finding a damp, mouldering US$2 note among their change. The bills were issued as a one-off to mark the US bicentenary in 1976 and are rarely seen anywhere but Hanoi these days - a sure sign of cash stashed long ago and only recently given an airing.